Ultrasonic waves have been widely used in medical applications, including diagnostics and therapy, and in many industrial applications, for welding, cutting, fiber optics technology, speed meters, etc. Diagnostic use of ultrasound waves includes using ultrasonic waves to detect underlying structures in an object or human body. An ultrasonic transducer is placed in contact with the tissue or object via a coupling medium, and high frequency (1-10 MHz) ultrasonic waves are directed to the tissue. Upon contact with the various underlying structures, the waves are reflected back to a receiver adjacent the transducer. By comparison of the signals of the ultrasonic waves sent with the reflected ultrasonic wave as received, an image of the underlying structure can be produced.
Three therapeutic medical uses of ultrasound waves include aerosol mist production, contact physiotherapy, and soft tissue ablation. The ultrasound contact physiotherapy procedure may cause a patient significant discomfort and/or pain, and skin may appear raw and damaged.
However, the necessity of direct contact with or without a coupling medium makes current methods undesirable. Some tissue conditions may be accessible to contact ultrasound devices but would be impractical for contact ultrasound treatment. For example, fresh or open wounds resulting from trauma, burns, surgical interventions are not suitable for direct contact ultrasound treatment because of the structural nature of the open wound and the painful condition associated with those wounds. Moreover, conventional contact ultrasound may have a destructive effect on these types of open wounds due to the close proximity of an oscillating tip of an ultrasonic transducer relative to the already damaged tissue surface. In general, conventional ultrasound therapy considers applicator placed on the skin and deep propagation of ultrasonic waves and much of the energy is wasted.